Study on Xu Xia-ke's travels of the extraordinary cold in the 17th century and the extra long heavy rain in Yunnan Province in 1638

This paper is translated and consolidated from the following papers: Study on Xu Xia-ke's Records of the Extraordinary Cold Caused by the Heavy Snow in the 17th Century (Geographical Research, v. 12, no. 3), and A Study on the Extra Long Autumn Rain in the Central Part of Yunnan in 1638 Based on Xu Xia-ke's Travels (Geographical Research, v. 14, no. 4). The translation and consolidation were done by Wong Yat Loon, Department of Urban and Environment Science, Peking University, Beijing 100871, China This revised version was published online in August 2006 with corrections to the Cover Date.     

地史重大转折期的环境变化学术讨论会综述

概述了地史重大转折期的环境变化学术讨论会４个方面的主要科学内容：古生代与中生代之交的全球环境变化,泥贫纪弗拉期与法门期之交的全球环境变化,元古宙与显生宙之交扔全球环境变化和地史重大转折期环境变化的研究方法。围绕上述内容,评述了发言人和专题发言人的主要科学资料和科学思想以及本次会议形成的共识。     

Processes of the deposition and vicissitude of Mu Us Desert, China since 150 ka B.P.

“Milanggouwan stratigraphical section” named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B. P. Studies show that the sedimentary form was induced by the growth and decline and confrontation each other between the winter monsoon and the summer monsoon of East Asia in the past 150 ka. Project supported by the National Natural Science Foundation of China (Grant No. 49473192).     

Laboratory sulfurisation of the marine microalga Nannochloropsis salina

To understand more fully the mode of preservation of organic matter in marine sediments, laboratory sulfurisation of intact cells of the cultured microalga Nannochloropsis salina was performed using inorganic polysulfides in seawater at 50°C. Solvent extractable and non-extractable materials were analysed by GC–MS and Py–GC–MS, respectively, to study the incorporation of sulfur into the microalgal organic matter. No GC-amenable sulfur-containing compounds were found in the extracts apart from some minor thiophenes with a phytanyl carbon skeleton. The residue after extraction and hydrolysis contained abundant macromolecular sulfur-containing moieties as revealed by the presence of dominant C₂₈–C₃₂ thiols, thiophenes, thianes and thiolanes in the flash pyrolysates. These products are thought to be formed from moieties derived from sulfurisation of C₂₈–C₃₂ diols and alkenols, characteristic lipids of N. salina. C₁–C₂ alkylated thiophenes were also found in the pyrolysates and probably result from moieties formed upon sulfurisation of carbohydrates. The highly resistant biomacromolecule (algaenan) synthesised by N. salina remains unaffected by sulfurisation. The non-hydrolysable residue isolated from the sulfurised N. salina thus comprises algaenan and (poly)sulfide-bound long alkyl chains. The sulfurisation experiments show that both selective preservation of algaenans and lipid and carbohydrate “vulcanisation” can be involved in the preservation of algal organic matter in marine environments.     

Thymol as a Biocide in Japanese Rainwater

Rainwater samples (wet-only; event samples) collected in Niigata in late autumn 1996 and springtime 1997 were used to assess the effectiveness of thymol as a biocide in Japanese rainwater. Upon collection each rainwater sample was divided into sub-samples, with thymol added to one sub-sample. Sub-samples with and without thymol were shipped to CSIRO, Australia, for chemical analysis. Comparison of analytical results for each pair of sub-samples proved the effectiveness of thymol in preventing biological action in this region where effects of rainwater microflaura and fauna on rainwater composition have not before been studied. Sub-samples without thymol exhibited lowered electrical conductivity, loss of the cations H⁺ and NH ₄ ^- , and loss of the anions HCOO^-, CH₃COO^-, C₂O ₄ ^2- , CH₃SO ₃ ^- and PO ₄ ^3- . Nitrate showed no change in all but one of the samples, indicating that ammonia was the preferred source of nitrogen for the biological processes that consumed the rainwater organic acids and phosphate. These results suggest that thymol is a suitable rainwater biocide for use under Japanese conditions.     

天文底片保存和我国天文底片数字化的建议

阐述了国际上天文照相底片数字化工作的进展:底片的保存、底片数字化的意义和相关技术。扼要地介绍了国际虚拟天文台的情况及其与底片数字化的关系。分析了我国天文底片资料的保存现状,并提出了底片数字化建议:成立由各天文台专家组成的全国底片数字化协调小组,建立各单位保存底片的信息库、改进底片的保存条件、有步骤地对有价值底片上的全部目标进行扫描,以便将其与现代高精度的观测资料相结合,开展有意义的课题研究。     

Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.     

The origin,type and preservation of organic matter of the Barremian–Aptian organic-rich shales in the Muglad Basin,Southern Sudan,and their relation to paleoenvironmental and paleoclimate conditions

Barremian–Aptian organic-rich shales from Abu Gabra Formation in the Muglad Basin were analysed using geochemical and petrographic analyses. These analyses were used to define the origin, type of organic matters and the influencing factors of diagenesis, including organic matter input and preservation, and their relation to paleoenvironmental and paleoclimate conditions. The bulk geochemical characteristics indicated that the organic-rich shales were deposited in a lacustrine environment with seawater influence under suboxic conditions. Their pyrolysis hydrogen index (HI) data provide evidence for a major contribution by Type I/II kerogen with HI values of >400 mg HC/g TOC and a minor Type II/III contribution with HI values <400 mg HC/g TOC. This is confirmed by kerogen microscopy, whereby the kerogen is characterized by large amounts of structured algae (Botryococcus) and structureless (amorphous) with a minor terrigenous organic matter input. An enhanced biological productivity within the photic zone of the water columns is also detected. The increased biological productivity in the organic-rich shales may be related to enhanced semi-arid/humid to humid-warm climate conditions. Therefore, a high bio-productivity in combination with good organic matter preservation favoured by enhanced algae sizes are suggested as the OM enrichment mechanisms within the studied basin.     

流化冰对于鲣鱼的保鲜效果研究

以远洋鲣鱼为研究对象,以传统淡水碎冰保鲜为对照,研究流化冰处理对鲣鱼的理化性质及微生物特性的影响。结果表明:(1)–4°C冷藏18d后,流化冰保鲜鱼肉pH值、TVB-N、TBA、a*值和菌落总数依次为5.57、10.2mgN/100g、2.87mg/100g、8.92和2.61lgCFU/g,而淡水碎冰保鲜鱼肉各指标已达6.05、20.3mgN/100g、6.60mg/100g、7.16和3.02lgCFU/g,故可知流化冰保鲜处理效果明显优于碎冰保鲜。(2)在25±1°C室温条件下,将冰与鱼放入保温箱内保鲜8h后,流化冰保鲜鱼肉的a*值、pH值、TVB-N、TBA、菌落总数和汁液流失率均显著低于空白和淡水碎冰保鲜处理组(P0.05)。流化冰保鲜可显著减缓鱼体的腐败进程、延长产品货架期,进而满足冰鲜水产品的远洋及长距离运输要求。     

Archean to Recent aeolian sand systems and their sedimentary record: Current understanding and future prospects

The sedimentary record of aeolian sand systems extends from the Archean to the Quaternary, yet current understanding of aeolian sedimentary processes and product remains limited. Most preserved aeolian successions represent inland sand‐sea or dunefield (erg) deposits, whereas coastal systems are primarily known from the Cenozoic. The complexity of aeolian sedimentary processes and facies variability are under‐represented and excessively simplified in current facies models, which are not sufficiently refined to reliably account for the complexity inherent in bedform morphology and migratory behaviour, and therefore cannot be used to consistently account for and predict the nature of the preserved sedimentary record in terms of formative processes. Archean and Neoproterozoic aeolian successions remain poorly constrained. Palaeozoic ergs developed and accumulated in relation to the palaeogeographical location of land masses and desert belts. During the Triassic, widespread desert conditions prevailed across much of Europe. During the Jurassic, extensive ergs developed in North America and gave rise to anomalously thick aeolian successions. Cretaceous aeolian successions are widespread in South America, Africa, Asia, and locally in Europe (Spain) and the USA. Several Eocene to Pliocene successions represent the direct precursors to the present‐day systems. Quaternary systems include major sand seas (ergs) in low‐lattitude and mid‐latitude arid regions, Pleistocene carbonate and Holocene–Modern siliciclastic coastal systems. The sedimentary record of most modern aeolian systems remains largely unknown. The majority of palaeoenvironmental reconstructions of aeolian systems envisage transverse dunes, whereas successions representing linear and star dunes remain under‐recognized. Research questions that remain to be answered include: (i) what factors control the preservation potential of different types of aeolian bedforms and what are the characteristics of the deposits of different bedform types that can be used for effective reconstruction of original bedform morphology; (ii) what specific set of controlling conditions allow for sustained bedform climb versus episodic sequence accumulation and preservation; (iii) can sophisticated four‐dimensional models be developed for complex patterns of spatial and temporal transition between different mechanisms of accumulation and preservation; and (iv) is it reasonable to assume that the deposits of preserved aeolian successions necessarily represent an unbiased record of the conditions that prevailed during episodes of Earth history when large‐scale aeolian systems were active, or has the evidence to support the existence of other major desert basins been lost for many periods throughout Earth history?